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14th Jan 2018, 6:58 pm | #1 |
Dekatron
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Replica PP8 6 Volt Battery (as used in Roberts RT1).
In another thread I mentioned that I've just fettled up a Roberts RT1 portable transistor radio, which originally used a long since obsolete PP8 6 Volt battery.
I could just have used a battery holder with four AA cells, but having found a scan of a PP8 from a source I can't now recall, for what little effort it involved, I thought I might just as well knock up a replica battery in which to house the 4 cell holder. Not a lot to say about it really. I made a box from scrap bits of oak, dimensioned to suit the battery scan, (approximately 15.5cms long x 5cms wide x 4cms deep). I sealed one end of the box with wood and left the other end open, (each side notched for clearance for the battery connectors), to which I attached a 2mm thick Paxolin panel fitted with two of the larger press-stud battery connectors as used in the Roberts RT1. Having inserted the battery container into the box, I fitted the Paxolin panel with four small brass c/s woodscrews. I printed the scan onto 100gsm paper, sprayed it with clear lacquer to fix the ink, then glued the paper to the box and to the removable end panel. Nothing more to say really - it does the job and looks well enough. (Must remember not to chuck it away when the batteries go flat!). Sorry I can't find the link to the battery scan, but if anyone would like it, I'll happily e-mail it if they PM me with their e-mail address. Better still if someone can add the link if they have it. Hope it's of interest.
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David. BVWS Member. G-QRP Club member 1339. |
14th Jan 2018, 7:16 pm | #2 |
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Re: Replica PP8 6 Volt Battery (as used in Roberts RT1).
You might like to post your scan in this thread:-
https://www.vintage-radio.net/forum/...d.php?t=109240
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Graham. Forum Moderator Reach for your meter before you reach for your soldering iron. |
14th Jan 2018, 7:45 pm | #3 |
Octode
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Re: Replica PP8 6 Volt Battery (as used in Roberts RT1).
That thread has been closed for while, Graham.
When I made a battery for mine I fixed a 4 x HP11 holder to two pieces of wood making a letter L shape, and fixed the studs on to the short piece. This then slid into a cardboard housing for cosmetic purposes. I'm not saying this is better but may be easier for those people who aren't as good at woodwork. Last edited by ThePillenwerfer; 14th Jan 2018 at 7:55 pm. |
14th Jan 2018, 7:54 pm | #4 | |
Dekatron
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Re: Replica PP8 6 Volt Battery (as used in Roberts RT1).
Quote:
http://www.royalsignals.org.uk/batteries/ http://www.royalsignals.org.uk/kd4hsh/index.html I've tried both of those to check, but they report thus: Forbidden. You don't have permission to access /batteries/ on this server. Additionally, a 403 Forbidden error was encountered while trying to use an ErrorDocument to handle the request. Don't know what's going on there?
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14th Jan 2018, 7:57 pm | #5 |
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Re: Replica PP8 6 Volt Battery (as used in Roberts RT1).
PP8 battery length = 200mm (approx.) so far as I know.
Lawrence. |
14th Jan 2018, 8:03 pm | #6 |
Octode
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Re: Replica PP8 6 Volt Battery (as used in Roberts RT1).
Royal Signals has just let me on fine.
I think the "Length—257mm" refers to the entire image, not the height of the battery. |
14th Jan 2018, 8:20 pm | #7 |
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Re: Replica PP8 6 Volt Battery (as used in Roberts RT1).
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14th Jan 2018, 8:27 pm | #8 |
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Re: Replica PP8 6 Volt Battery (as used in Roberts RT1).
I've reopened it.
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Graham. Forum Moderator Reach for your meter before you reach for your soldering iron. |
14th Jan 2018, 9:01 pm | #9 |
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Re: Replica PP8 6 Volt Battery (as used in Roberts RT1).
Thanks Graham.
Hope these are OK. (If the thumbnail is opened, and the opened picture is copied and saved, it should come out the correct size, as stated on the side tabs of each picture - 257 mm full length). Ooops - posted in this thread rather than the battery scan thread, so I'll post it there too. I can't delete this post - only edit it.
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David. BVWS Member. G-QRP Club member 1339. Last edited by David G4EBT; 14th Jan 2018 at 9:05 pm. Reason: Posted in wrong section. |
14th Jan 2018, 9:13 pm | #10 | |
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Re: Replica PP8 6 Volt Battery (as used in Roberts RT1).
Quote:
Yes, the 257mm is the full length of the artwork. With it being stated on that glue-tab, it's a bit misleading.
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David. BVWS Member. G-QRP Club member 1339. |
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14th Jan 2018, 9:37 pm | #11 |
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Re: Replica PP8 6 Volt Battery (as used in Roberts RT1).
The one you made David looks to be about 45mm shorter than the original, the original was approx. 200mm in height when stood on end, the radio is approx 250mm wide, take away the thickness of both sides of the cabinet and the plywood blocks and that leaves a nice snug space for a PP8 battery replica and its connector terminals without it sliding around inside the radio.
Now found a link for the full book referring to the book page link I posted earlier that gives battery dimensions for many types (latter part of the book for PP8 etc) if its of any use: https://archive.org/details/CROMPTON...renceBook3rdEd. Lawrence. |
14th Jan 2018, 9:59 pm | #12 |
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Re: Replica PP8 6 Volt Battery (as used in Roberts RT1).
Thanks for the link Lawrence - most useful.
I've just measured the space in the back of the set and you're correct in terms of the space - as you say, a 200mm long battery would fit snugly with no risk of sloshing about. Not having found any other scan, I simply made the replica from the one that I'd found, to the dimensions given. Clearly too short it seems, but the width and depth do seem to be the correct size. Forum member 'Batterymaker' doesn't have a PP8 scan on his site as far as I can tell, but interestingly, this YouTube video of his RT1 clearly shows a full length battery: https://www.google.co.uk/url?sa=t&so...T6TslGPynkPXFB 200mm does look awfully long for a battery - I don't recall having ever seen an original one.
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David. BVWS Member. G-QRP Club member 1339. |
15th Jan 2018, 7:59 am | #13 |
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Re: Replica PP8 6 Volt Battery (as used in Roberts RT1).
Morning David.
Boy as always outstanding workmanship looks the part. Kevin |
15th Jan 2018, 9:50 am | #14 |
Dekatron
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Re: Replica PP8 6 Volt Battery (as used in Roberts RT1).
Nice of you to say so Kevin, but careless work I'm afraid!
I initially printed off the artwork and glued it up to see how it fitted into the set. It came out at 15.5cms long x 5cms wide x 4cms deep, and fitted nicely, so I just assumed it was correctly sized, made a box to fit the artwork and the end result seemed to look the part. It wasn't until Lawrence gave the true dimensions of a PP8 that I discovered that as made, mine is well undersized. The true dimensions should be 20.08cms x 6.5mm x cms x 5.16cms. I've resized the artwork to print out that size and have glued a sample together. The pics below show the true size of a PP8 as compared to my stunted one. The full sized mock up is shown in the rear of the RT1 and as can be seen, runs the full length of the battery compartment. So at this stage, at best, it's A- for effort, C+ for attainment. Ho hum - back to the bandsaw then! I take inspiration from Sir Winston Churchill on success and failure: "Success is the ability to go from failure to failure without losing your enthusiasm." Quite so!
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David. BVWS Member. G-QRP Club member 1339. |
15th Jan 2018, 2:04 pm | #15 |
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Re: Replica PP8 6 Volt Battery (as used in Roberts RT1).
This web page http://www.vintageradio.me.uk/radconnav/homerad.htm which features pages from the old Home Radio catalogue is always useful for getting the dimensions of old obsolete Ever Ready batteries. The PP8 is shown here http://www.vintageradio.me.uk/radcon...961/batts3.jpg and is 2 9/16" x 2 1/16" x 7 15/16" in old money! This converted to metric is 201.6mm x 52.38mm x 65.08mm so looks about right as in your last post David.
Peter |
15th Jan 2018, 2:12 pm | #16 |
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Re: Replica PP8 6 Volt Battery (as used in Roberts RT1).
Could you not accept that your 1st brilliant construction has just gone a little flat with use?
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15th Jan 2018, 2:15 pm | #17 |
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Re: Replica PP8 6 Volt Battery (as used in Roberts RT1).
That is great work.
I'm very impressed with your PP8 battery replica, it looks the part in the radio. I'm sure the vision of what it could look like, in your mind, motivates the hard work and the extra mile & effort you go to, to do a job properly. It shows great imagination, combined with an excellent work ethic, skill and artistry. |
15th Jan 2018, 4:36 pm | #18 |
Dekatron
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Re: Replica PP8 6 Volt Battery (as used in Roberts RT1).
It's really kind of you (and others), to heap praise on what - after all - is just a little wooden box, (and the wrong size at that!), with paper stuck on it.
At risk of being accused of going 'off piste' and starting a mutual back-slapping session, this is far more deserving of the epithets, 'going the extra mile, doing the job properly, skill and artistry': https://www.vintage-radio.net/forum/...d.php?t=141753 Home brew at its very best - no effort spared.. Respect!
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David. BVWS Member. G-QRP Club member 1339. |
15th Jan 2018, 4:52 pm | #19 | |
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Re: Replica PP8 6 Volt Battery (as used in Roberts RT1).
Quote:
I'm on the case though - I think 4x C cells in a battery holder will have more capacity, and fit snugly inside a correctly sized PP8 'wooden overcoat'. As I type, a holder is winging its way to me from e-bay. "Use what talents you possess: The woods would be very silent if no birds sang there except those that sang best". Henry van Dyke. (1852 – 1933)
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David. BVWS Member. G-QRP Club member 1339. |
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15th Jan 2018, 7:58 pm | #20 |
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Re: Replica PP8 6 Volt Battery (as used in Roberts RT1).
As somebody who has made many, many mistakes over the years, I am a great believer in the old adage 'He who never made a mistake never made anything'. Along with a version I heard some years ago, perhaps a bit too modern for this forum 'The designer who never blew a chip is a bad designer. He never designed anything'.
Your PP8 replica looks great, your woodwork skills are excellent. Think of it as being V1.0. It is a starting point for another one, probably better as it will be closer to the right size. |